DE2657808C2 - Low-shrinkage curable polyester molding compositions and process for their production - Google Patents

Description

characterized in that the polyalkylene ether copolymer is a graft and / or copolymer mixture, the radical polymerization of ethylenically unsaturated polyalkylene ethers and at least one ethylenically unsaturated monomer has been obtained in an amount of 0.1 to 25% by weight, based on the total weight of components a) and b), is used.

2. Curable, unsaturated polyester molding compositions according to claim 1, characterized in that the Polyalkylene ether copolymer consists of a graft polymer mixture, which by radicalsU-> Graft polymerization of ethylenically unsaturated hydroxy group-containing polyalkylene ethers and at least an ethylenically unsaturated monomer has been obtained.

3. Curable, unsaturated polyester molding compositions according to claim 1, characterized in that the Polyalkylene ether copolymer consists of a copolymer mixture that is formed by radical copolymerization of ethylenically unsaturated, copolymerizable polyalkylene ethers and at least one Ethylenically unsaturated monomers has been obtained.

4. Process for the preparation of unsaturated curable in the presence of conventional polymerization initiators Polyester molding compositions according to Claim 1

a) at least one ethylenically unsaturated copolymerizable polyester,

b) at least one ethylenically unsaturated copolymerizable monomeric compound,

c) a polyalkylene ether copolymer and optionally

d) thickeners. Inhibitors. Fillers, lubricants. Reinforcing agents, inert solvents, Polymerization accelerators, shrinkage-reducing additives and / or others usually auxiliary materials used when using polyester molding compounds,

characterized in that 0.1 to 25 parts by weight of a polyalkylene ether copolymer are added 100 parts by weight of a mixture of components a) and b) are added, the polyalkylene ether copolymer a graft and / or copolymer mixture is used, which by radical Polymerization of ethylenically unsaturated polyalkylene ethers and at least one ethylenically unsaturated Monomers has been obtained.

The present invention relates to low-shrinkage curable, unsaturated polyester molding compositions which are ethylenic unsaturated polyesters, copolymerizable ethylenically unsaturated monomeric compounds and a polyalkylene ether copolymer contain, have an improved storage stability and after curing a result in a smooth surface with a high surface gloss, and a process for their production.

Unsaturated polyester molding compounds are used for the production of fibers, such as glass, Asbestos or textile fiber reinforced objects are used and are widely used in the Manufacture of products such as body parts, furniture such as chairs, heating enclosures, scarf: etc. Such Products stand out against metals, among other things. by light weight, great strength compared to the Weight, corrosion resistance and their flexibility in the design of the parts. A large The disadvantage of the known products is that they have rough, wavy surfaces with characteristic Have reinforcement fiber pattern. These rough surfaces are at least partially due to the polymerization of the resin occurring shrinkage. Although this is probably not the case the only circumstance for the poor surface quality of the moldings. so he is still considered a predominant one Factor viewed.

For many uses is the surface smoothness of the fiber reinforced resin laminates insignificant. For certain purposes, however, if there is no subsequent treatment or only a thin layer Painting is carried out, with which the surface roughness can not be compensated z. B. at

so surface parts for motor vehicles, the mostly rough surface is undesirable. To improve the The surface smoothness of molded articles reinforced by glass fibers are known to a limited extent, such as the use of resin-enriched gel coatings or veil-like glass fiber surface mats. In both cases, a resin-rich surface is obtained into which the glass fiber strands are immersed so that they are less visible. However, these procedures require additional treatment.

levels and additional costs.

Often is desirable. To give away moldings with a coat of paint that gives them a smooth, metal-like, high-gloss finish Gives appearance. In practice, this is done using the time and manpower required Dry coating process, through which the surface smoothness of the glass fiber reinforced plastic part before the

Application of the top coat is improved. Such a method for improving the surface quality is currently used in the manufacture of car bodies made of glass fiber reinforced polyester. The cost of dry polishing is a significant factor in the total cost of the Finishing of the bodies.

Processes have already become known which cause the curing shrinkage of unsaturated polyester resins > Addition of thermoplastic solutions in vinyl monomers to fillers and glass fiber reinforcements To reduce polyester molding compounds or to eliminate them entirely, with a continuous phase of essentially network! unsaturated polyester resin and an opaque, thermoplastic polymer dispersed therein containing phase is formed.

A distinction is made between one-component and two-component systems. In the one-component system, the Thermoplastic either dissolved in the unsaturated polyester resin or emulsified. In both cases one forms dispersed phase at the latest during curing. The two-component system is incompatible between unsaturated polyester resin and thermoplastic phase before curing, for example at Polymers or copolymers made from styrene or its derivatives. Because these systems are in contrast to the clear One-component systems are easy to color, they are often used in spite of certain disadvantages. Disadvantageous However, it turns out that the monomer-containing thermoplastic phase separates out prematurely (particle enlargement), as soon as the system is no longer stirred. This phenomenon occurs especially when Store low-viscosity, filler-free or low-filler mixtures for several hours or even days before processing will.

This leads to uneven phase distribution in the molded part and thus to non-reproducible processing results. The same applies to similar unsaturated polyester resin mixtures that contain fillers and glass fiber, which are processed in the wet pressing process - without prior thickening with alkaline earth oxides will. The surfaces of the molded parts deteriorate as the molding compositions continue to be stored Surfaces.

In the case of glass mats (prepregs) made from thickened with alkaline earth oxides. Containing fillers and fiberglass reinforcements Molding compounds based on unsaturated polyester resins, this effect leads to a high degree of stickiness the mat, which makes it difficult to handle the cover film properly.

DE-OS 24 02 739 also discloses curable resin mixtures, for example of a) an unsaturated polyester resin, a terminally unsaturated vinyl ester resin or mixtures thereof, b) at least one monomer copolymerizable therewith and c) a polymeric low-profile additive which contain as stabilizing agent an anionically polymerized block copolymer of the formulas Bx-Ay and Ay-Bx-Ay in amounts of 0.1 to 5% by weight, based on components a) and b), and where B is a monoaikenyl aromatic monomer , a conjugated diene monomer or a mixture thereof polymerized in a block segment and A are polymerized ethylene oxide units and χ and y each have a value of at least about 25. The linear block copolymers produced by anionic polymerization from so-called living polystyrene and ethylene oxide have the disadvantage that they can only be produced from a limited number of monomers containing no Zerewi.tinoff active hydrogen atoms, namely monoalkenyl aromatic monomers and conjugated diene monomers that the stability improvement achievable with the block copolymers is limited to the addition of very specific polymeric low-profile additives. The linear block copolymer stabilizers mentioned can only be used to stabilize unsaturated resin mixtures which contain thermoplastics as low-profile additives that are formed by polymerizing alkenyl-aromatic monomers, so-called polyalkenyl-aromatic thermoplastics, and / or conjugated dienes , so-called polydiene rubbers. be produced.

It was the object of the present invention. curable in the presence of conventional polymerisation initiators, To develop unsaturated polyester molding compounds that cure with little shrinkage and molded parts with a smooth surface and improved surface gloss.

This object is achieved by unsaturated polymerization initiators curable in the presence of conventional polymerization initiators Polyester molding compounds

a) at least one ethylenically unsaturated copolymerizable polyester,

b) at least one ethylenically unsaturated copolymerizable monomeric compound,

c) a polyalkylene ether copolymer and optionally

d) thickeners, inhibitors, fillers, lubricants, reinforcing agents, inert solvents, Polymerization accelerators, shrinkage-reducing additives and / or others usually at the use of auxiliary materials used in polyester molding compounds,

where the polyalkylene ether copolymer is 0.1 to 25% based on the total weight of the components a-b, a graft and / or copolymer mixture is used, which by radical polymerization of Ethylenically unsaturated polyalkylene ethers and at least one ethylenically unsaturated monomer has been. t> o

Graft and / or copolymer mixtures in the context of the invention are to be understood as meaning mixtures which consist of consist of the following components:

i) from unchanged, ethylenically unsaturated polyalkylene ether

ii) from graft and / or copolymer and

iü) from pure homopolymer or optionally homo- and copolymer, obtained by polymerization of the ethylenically unsaturated monomers.

The curable, unsaturated polyester molding compositions according to the invention can be used to produce cured fiber-reinforced Plastic molded parts can be produced with a smooth surface without the need for the above to use the additional surface smoothing method described. Surprisingly showed sü ± Furthermore, that the polyester molding compositions according to the invention form extremely storage-stable emulsions, which for example have not yet separated after storage for 24 hours at room temperature.

The curable, unsaturated polyester molding compounds are made from

a) at least one ethylenically unsaturated, copolymerizable polyester,

b) at least one ethylenically unsaturated, copolymerizable monomeric compound,
ίο c) a polyalkylene ether copolymer and optionally

d) thickeners, inhibitors, fillers, lubricants, reinforcing agents, inert solvents, Polymerization accelerators, shrinkage-reducing additives and / or others usually at the use of polyester molding compounds used auxiliaries,

0.1 to 25 parts by weight of the polyalkylene ether copolymer to 100 parts by weight of a mixture of the Components a) and b) is added and where the polyalkylene ether copolymer is a graft and / or copolymer mixture is used, which is obtained by radical polymerization of ethylenically unsaturated Poiyalkylenäthern and at least one ethylenically unsaturated monomer has been obtained.

The starting components which can be used for the production of the curable, unsaturated polyester molding compositions a) to d) do the following:

a) As unsaturated polyesters, the customary polycondensation products from polyvalent polyesters, in particular, are suitable dibasic carboxylic acids and their esterifiable derivatives, in particular their anhydrides, which are linked in an ester-like manner with polyhydric, in particular dihydric alcohols, and optionally additional residues of monohydric carboxylic acids and / or residues of monohydric alcohols and / or residues of hydroxycarboxylic acids contain, at least some of the radicals being copolymerizable via ethylenically unsaturated Groups must have.

Suitable polyhydric, in particular dihydric, optionally unsaturated alcohols are the usual, in particular acyclic groups, cyclic groups as well as both types of groups Alkanediols and oxaalkanediols, such as. B. ethylene glycol, propylene glycol-1,2-propanediol-13, butylene glycol-13, 1,4-butanediol. 1,6-hexanediol, 2,2-dimethylpropanediol-13, diethylene glycol, triethylene glycol, polyethylene glycol, 1,2-cyclohexanediol, 2,2-bis (p-hydroxycyclohexyl) propane, trimethylolpropane monoallyl ether or 1,4-butenediol. Furthermore, monohydric, trihydric or higher alcohols, such as. B. ethylhexanol, fatty alcohols, Benzyl alcohol, l, 2-di- (allyioxy) -propano! - {3), glycerol, pentaerythritol or trimethylolpropane in subordinate Quantities are also used. The polyhydric, especially dihydric alcohols are generally used in stoichiometric or approximately stoichiometric amounts with polybasic, in particular dibasic carboxylic acids or their condensable derivatives implemented.

Suitable carboxylic acids or their derivatives are dibasic olefinically unsaturated, preferably ex, / i-olefinically unsaturated carboxylic acids, such as. B. maleic acid, fumaric acid, chloromaleic acid, itaconic acid, citraconic acid, methylenglutaric acid and mesaconic acid or their esters or preferably their anhydrides. Other dibasic, unsaturated and / or saturated, as well as aromatic carboxylic acids, such as, for. B. succinic acid, glutaric acid, «-Methylglutaräure. Adipic acid, sebacic acid, pimelic acid, phthalic anhydride, o-phthalic acid, isophthalic acid, terephthalic acid, dihydrophthalic acid, tetrahydrophthalic acid, tetrachlorophthalic acid, 3-, 6-endomethylene-l, 23,6-tetrahydrophthalic acid, trihydrophthalic acid, trihydrophthalic acid, and also monohydrophthalic acid, endomethylene-tetrachloroic acid, endomethylene-tetrachloroic acid, tri-hydrophthalic acid, and also monohydrophthalic acid, endomethylene-tetrachloroic acid, and also monohydrophthalic acid, endomethylene-tetrachloroic acid higher basic carboxylic acids, such as. B. ethylhexanoic acid, fatty acids, methacrylic acid, propionic acid, benzoic acid, 1,2,4-benzenetricarboxylic acid or 1,2,4,5-benzenetetracarboxylic acid. Maleic acid or its anhydride and fumaric acid are preferably used. Since the maximum crosslinking capacity present in such polyesters is great

so plays a role in the performance of the low-profile system, the largest part, i.e. H. 50 to 100% that in the

Polyester built-in dicarboxylic acids can be unsaturated.

Mixtures of unsaturated polyesters, including those in the vinyl monomers (b) only to a limited extent Are soluble and easily crystallize can also be used to advantage. Such easily crystallizing unsaturated polyesters can e.g. B. from fumaric acid, adipic acid, terephthalic acid, ethylene glycol, 1,4-butanediol, 1,6-hexanediol and neopentyl glycol.

The unsaturated polyesters have acid numbers from 10 to 200, preferably from 20 to 85 and medium Molecular weights from about 800 to 6000, preferably from about 1000 to 4000.

The amorphous and optionally crystallizable unsaturated polyesters are in general by melt condensation or condensation under azeotropic conditions from their starting com-

W) components produced by continuous or discontinuous processes.

Regarding the composition of unsaturated polyesters, see the book by H.V. Boenig Unsaturated Polyesters: Structure and Properties, Amsterdam, 1964. The invention curable, unsaturated polyester molding compounds generally contain 10 to 70, preferably 15 up to 50% by weight of unsaturated polyester, based on the total weight of components (a) and (b).

b) The copolymerizable, ethylenically unsaturated monomeric compounds are usually used Manufacture of saturated polyester molding compounds used allyl and preferably vinyl compounds in Question how styrene, substituted styrenes such as p-chlorostyrene or vinyl toluene, esters of acrylic acid and

Methacrylic acid with alcohols containing 1 to 18 carbon atoms, such as methyl methacrylate, Butyl acrylate, ethylhexyl acrylate, hydroxypropyl acrylate, dihydrodicyclopentadienyl acrylate, butanediol diacrylate and (meth) acrylic acid amides, allyl esters such as diallyl phthalate, and vinyl esters such as ethyl oxanoic acid vinyl ester, Vinyl pivalate and others. Mixtures of the olefinically unsaturated compounds mentioned are also suitable Monomers. Preferably suitable as component b) are styrene, A-methylstyrene, chlorostyrene, Vinyl toluene, divinyl benzoil and diallyl phthalate. Component (b) is in the polyester molding compositions generally in a menu from 20 to 70, preferably from 30 to 50% by weight, based on the total weight of components (a) and (b) included.

c) Graft and / or copolymer mixtures are used as suitable polyalkylene ether copolymers, by radical polymerization of ethylenically unsaturated polyalkylene ethers and at least an ethylenically unsaturated monomer can be obtained. Those which can be used according to the invention Polyalkylene ether copolymers, the average molecular weights of about 1000 to 1,000,000, preferably from about 3,000 to 100,000 are used in such an amount of the polyester molding composition incorporated that this 0.1 to 25 wt .-%, preferably from 10 to 20 wt .-%. based on the total weight of components (a) and (b) on Polyalkylenäthermischpolymcrisaten (c).

For the production of the polyalkylene ether copolymers are ethylenic as a starting component unsaturated polyalkylene ethers with molecular weights from 500 to 20,000, preferably from 2000 to 10,000 used.

Saturated polyalkylene ethers can be obtained, for example, by reacting one or more alkylene oxides having 2 to 4 carbon atoms in the alkyl radical with a starter molecule which contains several bonded active hydrogen atoms. Suitable alkylene oxides are, for example, ethylene oxide, 1,2-propylene oxide, 1,3-propylene oxide, epichlorohydrin, 1,2-butylene oxide, 1,3-butylene oxide and tetrahydrofuran, ethylene oxide and 1,2-propylene oxide being preferably used. The alkylene oxides can be used individually, alternately in succession or as mixtures. Examples of starter molecules that can be considered are: water; Ammonia; Amines, such as ethylenediamine, hexamethylenediamine, tolylenediamine, diamino-diphenylmethane or hydrazine; Amino alcohols such as mono- and diethanolamine, dicarboxylic acid. such as adipic acid, butyric acid and terephthalic acid; and preferably polyhydroxy compounds with 2 to 8, preferably 2, hydroxyl groups such as glycerol, trimethylolpropane, pentaerythritol, sorbitol, sucrose and preferably ethylene glycol, propylene glycol and diethylene glycol. The polyalkylene ethers, which can be straight-chain, partially branched or branched, have hydroxyl numbers from 900 to 5, preferably from 55 to 10, depending on their functionality and molecular weight.

For the purposes of the invention, unsaturated polyalkylene ethers are used. Such unsaturated Polyalkylene ethers can, for example, by reacting a saturated, hydroxyl-containing polyalkylene ether with an organic compound that has both an ethylenically unsaturated double bond as well a reactive group, for example a hydroxy, alkoxy, carboxyl, carbalkoxy, epoxy, isocyanate group or contains a dicarboxylic anhydride residue. Suitable organic compounds of named type are, for example, ethylenically unsaturated carboxylic acids and their derivatives, such as acrylic acid and methacrylic acid; unsaturated carboxylic acid alkyl esters with 1 to 18 carbon atoms in the alcohol radical, for example Hydroxypropyl acrylate, trimethylolpropane diacrylate, trimethylolpropane monomethacrylate, pentaerythritol diacrylate and dihydroxyethylaminoethyl methacrylate, the compounds mentioned optionally in a mixture with di- and / or polyisocyanates or partially reacted with di- and / or polyisocyanates for Apply; N-methylol acrylamide. N-butoxymethyl methacrylamide and maleic anhydride. As Di- and / or polyisocyanates are for example: hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate and polyphenylene polymethylene polyisocyanate. Unsaturated Polyalkylene ethers can also be obtained by adding an organic compound containing both is ethylenically unsaturated and contains a hydroxyl, carboxyl or epoxy group as a reactant, for example as a starter molecule or as an alkylene oxide, used in the production of the polyalkylene ether will. Examples of such organic compounds are: Unsaturated carboxylic acids and Carboxylic anhydrides, e.g. B. maleic acid and maleic anhydride, fumaric acid, crotonic acid. Propenyl succinic anhydride, halogenated maleic acid and halogenated maleic anhydride; unsaturated polyvalent Alcohols e.g. B. 2-butene-1,4-diol, glycerallyl ether, trimethylolpropane allyl ether, pentaerythritallyl ether, Pentaerythritol vinyl ether, pentaerythritol diallyl ether and 1-butene-3,4-diol; and unsaturated epoxides, e.g. B. 1-vinylcyclohexane-3,4-epoxide, Butadiene monoepoxide, glycidyl vinyl ether (l-vinyloxy-2,3-epoxypropane), glycidyl methacrylate and allyl glycidyl ether (3-allyloxypropylene oxide). For the production of the unsaturated polyalkylene ethers the ethylenically unsaturated organic compounds mentioned are used in such amounts that in the end product 0.1 to 6 mol, preferably 0.1 to 3 mol and in particular 0.5 to 2 mol of unsaturated units per mole of polyalkylene ether are included.

The ethylenically unsaturated units can be randomly distributed in the polyalkylene ether or in the bo are essentially in the form of end groups. Unsaturated polyalkylene ethers are preferably used with essentially terminal ethylenically unsaturated units.

The saturated and unsaturated polyalkylene ethers can be prepared by known processes such as those described in US Pat. Nos. 3,346,557, 3,275,606 and 3,280,077. The reaction is generally carried out at temperatures from 0 ° to 130 ° C. under pressure or optionally without pressure. It is possible to use acidic catalysts, such as Lewis acids, or basic catalysts, such as alkyl hydroxides or alcoholates. The reaction may also be in the absence of catalysts at temperatures of 50 to 200 ⁰ C performed.

s / »υ»

Ethylenically unsaturated monomers are another starting component for the preparation of the polyalkylene ether copolymers. When ethylenically unsaturated monomers that can be used as such or in the form of mixtures, such as are dienes such as butadiene, isoprene and ^1,6-Hexad: s; optionally substituted styrenes, such as styrene,, r-methylstyrene, methylstyrene. Butylstyrene, chlorostyrene, vinyl compounds, for example vinyl esters, such as vinyl acetate, vinyl propionate, vinyl butyrate; Vinyl ethers, such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone; Acrylic monomers and substituted acrylic monomers, such as acrylonitrile, acrylic acid, methacrylic acid, (meth) acrylates with 1 to 18 carbon atoms in the alcohol radical, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, methyl methacrylate, cyclohexyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate; Ν, Ν-dimethylacrylamide; N-butyl acrylamide; Maleic acid and its derivatives, such as maleic anhydride and dialkyl ester with 1 to 18 carbon atoms in the alkyl radical. For example dimethyl maleate and fumaric acid and their dialkyl esters with 1 to 18 carbon atoms in the alkyl radical. Ethylenically unsaturated monomers such as vinyl aromatics, in particular styrene and methyl styrenes, are preferably used; (Meth) acrylic acid esters, in particular methyl methacrylate and 2-ethylhexyl acrylate, and vinyl esters, in particular vinyl acetate.

The amount of ethylenically unsaturated used in the radical graft and / or copolymerization Monomers is generally from 99.5 to 70% by weight, preferably from 99 to 80% by weight, based on the total weight of the mixture of monomers and ethylenically unsaturated polyalkylene ethers.

The graft and / or copolymerization can be activated thermally or by irradiation. For the polymerization, however, free radical-forming catalysts are preferably used in amounts from 0.01 to 10% by weight, preferably from 0.05 to 3% by weight, based on the weight of the monomer. The types known for vinyl polymerization are used as catalysts which form free radicals. For example, peroxides such as dibenzoyl peroxide, acetyl peroxide, ben: zoyl hydroperoxide, di-tert-butyl peroxide, lauroyl peroxide, cumene hydroperoxide, di-a-cumyl peroxide; Percarbonates such as diisopropyl peroxydicarbonate; Azo compounds such as nc. .V-Azobis-isobutyronitrile, λ, <v'-Azo-2-methylbutyronitrile, dimethyl- ^.

ar'-azoisobutyrate; Redox systems such as dibenzoyl peroxide benzoin; Persulfates and perborates. Mixtures of Catalysts can also be used.

The introduction of the catalyst into the reaction mixture is necessary for the graft and / or copolymerization to take place not decisive. For example, a suitable catalyst can be dissolved in the monomer and this solution added to the heated unsaturated polyalkylene ether, or the catalyst is used submitted to polyalkylene ether, heated and then allows the monomer continuously or in portions to run in unsaturated Polyalkylenälhcr. You can also use all three components, the monomer, the unsaturated Polyalkylene ether and the catalyst, mix and heat together or add the catalyst to the Bring in the reaction mixture of monomers and unsaturated polyalkylene ether. Which method the Preference is given, depends on the proportions of the polyalkylene ether-Moriomeres and the reaction conditions away.

Although the graft and / or copolymerization is preferably carried out without diluents or solvents is carried out, so is the use of organic solvents, such as substituted or unsubstituted Aromatics, carboxylic acid esters ^ alcohols. Ketones, ethers, (cyclo) aliphatic hydrocarbons and halogenated hydrocarbons are not excluded. If graft and / or copolymers with lower Molecular weights are produced, the addition of molecular weight regulators, for example mercaptans, to be appropriate.

The reaction temperature depends on the monomer chosen and on the catalyst system used. It is in general between 50 ⁰ C and 180 ⁰ C, preferably between 70 ° and 160 ° C, with reaction times are from 0.5 to 20 hours. However, it can also be polymerized at lower or higher temperatures, if appropriate also under pressure, for example between 1 and 10 bar. The graft and / or copolymerization can be carried out batchwise or continuously. It is advantageous to carry out the reaction in an inert atmosphere, e.g. B. in the presence of nitrogen and to ensure thorough mixing, for example by stirring, of the reactants. Residues of unreacted monomers, if they are volatile, can be separated off under reduced pressure or by steam distillation.

The graft and / or copolymer mixtures obtained, which, as already stated, are made from unchanged Ethylenically unsaturated polyalkylene ethers, from graft and / or copolymer and from pure homopolymer or optionally homo- and copolymers of the polymerized unsaturated monomers, have average molecular weights of 1,000 to 1,000,000, and are soluble or soluble in styrene at least swellable. The graft and copolymers have ordered structures in a comb shape, with the The teeth are grafted mainly from vinyl polymers and the back is made up of polyalkylene ethers is, while with the copolymers the teeth predominantly from the. Polyalkylene ethers exist and the - Back is represented by the vinyl polymer. The products form with the unsaturated polyesters (a) and Ethylenically unsaturated copolymerizable monomeric compounds (b) sufficiently stable emulsions and can also be mixed with thermoplastic, polyether-free thermoplastics which may contain carboxyl groups Polymers are used without losing the advantages achieved.

The polyalkylene ether copolymers are the curable, unsaturated polyester molding compositions in one Amount from 0.1 to 25% by weight, preferably from 10 to 20% by weight, based on the total weight of the Components a) and b) incorporated.

n5 The following polyester resin build-up configurations falling under point d) come into consideration, for example: thickeners, for example based on alkaline earth oxides such as calcium oxide. Calcium hydroxide, magnesium hydroxide and preferably magnesium oxide and mixtures of these oxides or hydroxides. These can too be partially replaced by zinc oxide.

The thickener content of the polyester molding compositions according to the invention is generally 0.5 ₍ 1 to 5, preferably 1 to 3 percent by weight, based on the mixture of components a) and b).

As inhibitors, the usual ones come into question, such as. B. hydroquinone, tert.-outylcatechol, p-benzoquin-, on, chloranil, nitrobenzenes, such as m-dinitrobenzene, thiodiphenylamine or salts of N-nitroso-N-cyclohexylhy-

droxylamine and their mixtures. The inhibitors are generally present in the molding compositions in an amount of ¹ % from 0.005 to 0.2, preferably from 0.01 to 0.1, percent by weight, based on components a) and b). contain.

The present invention ^r, curable unsaturated polyester molding compositions are also mostly conventional L ₁ J fillers, reinforcing materials, lubricants and optionally inert solvents, Polymerisationsbeschleu-

^ ₁ niger and / or other auxiliaries usually used in the processing of polyester molding compounds

j 'added.

J Suitable fillers are e.g. B. usual fine powder or granular inorganic or organic fillers, such as

'' Chalk, kaolin, quartz flour, dolomite, barite, metal powder, cement, talc, kieselguhr, wood flour, wood shavings, Pigments and the like.

Inorganic or organic fibers or flat fibers, if appropriate, come into consideration as reinforcing materials j fabrics woven from it, e.g. B. those made of glass. Asbestos, cellulose and synthetic organic high polymers.

The fillers and reinforcing materials can be used in amounts of 5 to 200 percent by weight, based on the components a) to c).

it Zinc, magnesium and calcium stearate as well as polyalkylene ether waxes are used as lubricants

into consideration.

AU continues. ^cr ? ^{£ 7} ? B? NcnfBl! S to be used? inert losun ^ niiue! come ketones. Ester. Koh! Enw2SEsr- ■ * ;; substances in amounts of up to 100 percent by weight, based on component a), are possible. Examples of shrinkage-reducing additives that may optionally be used in addition to the component are, for example, thermoplastic polymers such as polystyrene, styrene copolymers, polyvinyl acetate or poly (meth) acrylates in amounts of 1 to about 30 percent by weight, based on components a) + b). Conventional polymerization accelerators, such as. B. heavy metal salts are also used.

The curable, unsaturated polyester molding compositions according to the invention preferably contain

20 to 75 parts by weight of at least one ethylenically unsaturated copolymerizable polyester (a).

15 to 75 parts by weight of at least one ethylenically unsaturated copolymerizable monomeric compound

(Federation

0.1 to 25 parts by weight of a polyalkylene ether copolymer.

The polyester molding compositions may, for example, by means of a press under a pressure of 0.4 to 15 N / mm are processed to 18O ⁰ C to form moldings at temperatures of 18 °. ² For this purpose, initiators, for example peroxides or other organic compounds which form free radicals when exposed to heat, are added to the curable, unsaturated polyester molding composition in amounts of 0.05 to 5% by weight. preferably from 0.! up to 3% by weight, based on the total weight of components a) and b). The following may be mentioned by way of example as initiators which produce free radicals: Benzoyl peroxide. tert-butyl peroctoate, tert-butyl perbenzoate, cyclohexanone peroxide, tert-dibutyl peroxide, azo compounds, for example azodiisobutyronitrile or other organic compounds with a labile carbon-carbon bond. The initiators are added to the unsaturated polyester molding compositions according to the invention only immediately before the molding composition is produced (prepreg) or before curing (wet pressing of the thickener-free, filler-containing resin system).

The parts and percentages given below relate to weight.

a) Unsaturated polyester resins

Polyester resin I.

An unsaturated polyester made from maleic anhydride, propylene glycol-1,2 and dipropylene glycol in a molar ratio 1: 0.78: 0.33 with an acid number of 30 and 0.493 equivalents of polymerizable double bonds / 100 g unsaturated, copolymerizable polyester (a) was after stabilization with 0.01 wt .-% hydroquinone, based on the total weight of components (a) and (b), 72% by weight dissolved in styrene.

Polyester resin II

An unsaturated polyester made from maleic anhydride and 1.2-propylene glycol with an acid number of 28 and 0.516 Equivalents of copolymerizable double bonds per 100 g of unsaturated, copolymerizable polyester (a) were after stabilization with 0.01 wt .-% hydroquinone, based on the total weight of the components (a) and (b) 65% dissolved in styrene

Polyester resin IH
The unsaturated polyester resins I and II were mixed in a weight ratio of 1: 1.

91.2 7.8 1.6 89.7 7.9 1.7 90.3 7.8 1.5

b) Production of styrenic polymer solutions

Polyalkylprtäthermischpolymerisat A Production of the polyalkylene ether copolymer

100 parts of a difunctional polyethylene glycol with a molecular weight of 9000, 1 part of maleic anhydride and 1.1 parts of succinic anhydride are melted with stirring and heated to 135 ° C. for one hour. The acid number of the macromeric polyethylene glycol modified in this way is 12.6.

H) In a 4 liter stirred vessel to a mixture of 2910 g of styrene and 30 g of rt-methylstyrene at 145 ° C in Presence of nitrogen in 50 minutes 60 g of the modified macromeric polyethylene glycol described above added. The reaction mixture is post-polymerized for 10 minutes at 145 ° C The cloudy styrenic solution obtained after cooling has a solids content of 51% by weight; it is made with styrene with the addition of 0.02% by weight of hydroquinone, based on the total weight, stabilized and 40% by weight

is set.

To determine whether a copolymer or a mixture of polystyrene and modified, macromeric polyethylene glycol was present, the polymer was taken up twice in tetrahydrofuran and precipitated by dropping it into petroleum ether with a boiling point of 65-95 ° C. The precipitated polymer was dried, pulverized and ^{extracted for 10 hours at 50 °} C. with distilled water. The elemental analysis of the polymer before and after the precipitation shows that it is a polystyrene copolymer which contains about 4% by weight, based on the total weight, of chemically bonded polyethylene glycol segments.

Elementary analysis:

CHO

calculated (complete copolymerization) found before extraction - ¹⁰ found after extraction

Polymer solution B (comparison)

In a 4 liter stirred vessel, a mixture of 2.970 g of styrene and 30 g of Λ-methylstyrene in the presence of Polymerized nitrogen at 145 ° C for one hour. The clear styrenic solution obtained after cooling has a solids content of 52 wt .-%, based on the total weight: it is based on styrene 40% by weight adjusted with 0.02% by weight hydroquinone, based on the total weight, stabilized. The border

viscosity of the polymer inToiuoi is i i 800.

Polymer solution C (comparison)

In a 2 liter reaction vessel equipped with a stirrer and reflux condenser, 150 g of toluene and 100 g of methyl methacrylate are heated to reflux temperature while passing in nitrogen. To the reaction solution is allowed to evenly in 2.5 hours, a solution of 2 g of dibenzoyl peroxide (75 wt ° / oig in water \ n 100 g of toluene and then 400 g of methyl methacrylate were added dropwise in 2 hours. The reaction mixture is to polymerize for 2 hours and After adding 2.5 g of dibenzoyiperoxide, the clear solution, diluted to a solids content of 40% by weight with 500 g of toluene, has a K value (1% in tetrahydrofuran, measured according to H. Fikentscher, Cellulose-Chemie 13 , (1932), page 58) of 42. To prepare a styrenic solution, the product is degassed for 10 hours under reduced pressure and then 30% by weight in styrene with the addition of 0.02% by weight of hydroquinone, based on the total weight, solved.

Polyalkylene ether copolymer D

Procedure ma ⁿ similar to that of the polymer solution C, but using as a template a mixture of 150 g toluene, 80 g of methyl methacrylate and 20 g of the modified Polyäthylenglykois macromer according PoIyalkylenäthermischpolymerisat A, the result is a weak dissolved in toluene copolymer having a K-value of 41.5 (measured 10% in tetrahydrofuran). The product is degassed and processed to a 30% by weight styrenic solution.

Polymer solution E (comparison)

In a 2 liter reaction vessel equipped with a stirrer and reflux condenser, a mixture of 150 g of toluene, 40 g of methyl methacrylate and 10 g of vinyl acetate is heated to reflux temperature. To the reaction mixture is allowed to a mixture of 360 g of methyl methacrylate and 90 g of vinyl acetate in 2 hours and then 2 g Dibenb5 peroxide for (75 gcw.- ^u / nig in water) dissolved in 64 g of toluene is added dropwise in 2.5 hours. After adding 3.5 g of dibenzoyl peroxide, the reaction mixture is allowed to polymerize out over the course of 6 hours. The solution is dried at 150 ° C. under reduced pressure for 10 hours. The polymer, which has a K value of 40.6 (measured 1% in tetrahydrofuran), is dissolved in 30% by weight in styrene.

Polyalkylene ether copolymer F

If the procedure is analogous to that of the polymer solution E, however, a mixture from is used as a template 150 g of toluene, 20 g of methyl methacrylate, 10 g of vinyl acetate and 20 g of the modified macromeric polyethylene glycol produced according to polyalkylene ether copolymer A, a copolymer with a K value is obtained of 43.7 (knife. 10% in tetrahydrofuran). The product is degassed and converted to a 30% strength by weight styrofoam Solution processed.

Polyalkylene ether copolymer G

A mixture of 50 g of toluene and 80 g of styrene is placed in a 1 liter reaction vessel equipped with a stirrer and reflux cooler. 80 g of 2-ethylhexyl acrylate, 40 g of the modified macromeric polyethylene glycol, produced _Ά

according to polyalkylene ether copolymer A, and 1 g of dibenzoyl peroxide (75% by weight in water) for one hour -

polymerized under reflux temperature A solution of 58 g of toluene and 2 g of dibenzoyl peroxide (75% strength by weight in water) is then added dropwise to the reaction mixture over a period of 3 hours. Polymerization is continued for 3 hours under reflux, a further 2 g of dibenzoyl peroxide (75% strength by weight in water) are added to the reaction mixture and the polymerization is allowed to complete in 2 hours. The toluene is distilled off under reduced pressure from the reaction mixture, which has a solids content of 64% by weight, based on the total weight, then 1 g of formic acid is added and the melt is ^{stirred at 130 °} C. for 1 hour. The polymer mixture is dissolved 40% by weight in styrene and added 0.02% by weight of hinon, based on the Gcsa

Polymer solution H

A commercially available polymethyl methacrylate is dissolved in 40% strength by weight in styrene.

Polyalkylene ether copolymer I

In a 2 liter reaction vessel equipped with a stirrer and reflux condenser, a mixture of 485 g Styrene, 10 g of a modified Poiyäthylenäthers, the by azeotropic esterification of a difunctional polyethylene glycol with a molecular weight of 9000 with acrylic acid in toluene up to a hydroxyl number smaller than 1 and distilling off the volatile constituents was prepared, and 5 g of Λ-methylstyrene while rinsing with Polymerized nitrogen at 140 ° C. for one hour.

The styrenic solution, which has a solids content of 54.4% by weight, based on the total weight, ^

is stabilized with styrene with the addition of 0.02% by weight of hydroquinone, based on the total weight 40% by weight set.

Polyalkylene ether copolymer K

If the procedure is analogous to that which was described for the preparation of the polymer solution 1, used however, instead of the polyethylene ether mentioned there, a monoolefinically unsaturated ethylene oxide polymer of molecular weight 8000, obtained by anionic polymerization of ethylene oxide and stopping the reaction was prepared with methyl methacrylate, a styrenic polymer solution is obtained with a Solids content of 50% by weight, based on the total weight. The solution is analogous to polymer solution I. stabilized and adjusted to 40% strength by weight. J.

Polymer solution I. (comparison) '

The procedure is analogous to that of polymer solution 1, but instead of the modified polyethylene ether a bifunctional, saturated polyethylene glycol with a molecular weight of 9000. Man this gives a cloudy styrenic solution with a solids content of 52% by weight, based on the total weight.

55 Example 1

a) To test a prepreg with low shrinkage properties, a glass mat with the following Reaction mixture soaked and stored for 6 days at 23 ° C between polyethylene sheets for maturation.

60 parts unsaturated polyester resin 11

40 parts of polyalkylene ether copolymer A

60 parts of filler chalk

90 parts filler chalk

3 parts calcium stearate t? 5

3 parts chrome green

3 parts of tert-butyl perbenzoate (50% by weight in plasticizer)

1.5 parts of magnesium oxide

After removing the cover film, the mat was pressed in a polished steel mold for 5 minutes at 145 ° C, 7.45 N / mm ² and the plate-shaped molded part, which has a glass content of approx. 30% by weight, based on the total weight, Demolded The surface of the molded part was homogeneous and shiny. A tool deposit could not be found.

b) If the procedure is analogous to a), however, instead of the polyalkylene ether copolymer A, the polymer solution is used B, a molding is obtained whose surface is inhomogeneous, shows spots and only a few Has gloss.

Example 2

To determine the emulsion stability, mixtures of 60 parts each of the unsaturated polyester resin were used HI and 40 parts of the polyalkylene ether copolymers A, D, F, I and K or the polymer solutions B, C, E and L and observed for signs of segregation in a test tube for 24 hours. the Results, which are compiled in the table below, show that the polyester molding compositions, the Polyalkylene ether copolymers contained, are stable emulsions in the observation period, while the Polyester molding compounds containing polymer solution rapidly separate and settle in 2 layers.

Example 3

To determine the emulsion stability, 27 parts of unsaturated polyester resin Hl, 15 parts of Polymerlö-J5 solution H and 3 parts of polyalkylene ether copolymer G and placed in a sealed test tube stored. The emulsion was stable at room temperature for an observation period of 20 days.

In a comparative experiment, 60 parts of unsaturated polyester resin HI and 40 parts of polymer solution H were used mixed and stored in a sealed test tube at room temperature. The emulsion was already completely separated after 24 hours.

ill (Λ

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Polymers Stability after 24 hours Storage at 25 ° C Poiyaikyienethermischpoiymerisat A stable Polymer solution B segregated Polymer solution C segregated Polyalkylene ether copolymer D stable Polymer solution E segregated Polyalkylene ether copolymer F stable Polyalkylene ether copolymer I stable Polyalkylene ether copolymer K stable Polymer solution L segregated

to

Claims (1)

Patent claims: 1. Unsaturated polyester molding compounds curable in the presence of conventional polymerization initiators a) at least one ethylenically unsaturated copolymerizable polyester, b) at least one ethylenically unsaturated copolymerizable monomeric compound. c) a polyalkylene ether copolymer and optionally d) thickeners ^ inhibitors, fillers, lubricants, reinforcing agents, inert solvents, Polymerization accelerators, shrinkage-reducing additives and / or others usually ίο auxiliary materials used when using polyester molding compounds,